<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
    *{
        padding:0;margin:0;
    }
    .row:after{
        content: "";
        display: table;
        clear: both;
    }
    ul{
        list-style: none;
    }
    a{
        text-decoration: none;
    }
    .nav{
        box-sizing: border-box;
        background: red;
        position: relative;
        
    }
    .nav li{
        float: left;
        border: 1px solid #333;
        margin-right: 10px;
    }
    .xiala{
        width:150px;
        background: pink;
        position: absolute;
        display: none;
    }
    .xiala1{
        width:150px;
        height: 50px;
        background: yellow;
        
    }
    .xiala2{
        width:150px;
        height: 50px;
        background: black;
        
    }
    .shangla:hover .xiala{
        display: block;
    }
    </style>
</head>
<body>
    <ul class="nav row">
        <li class="shangla">寿裳岬1号
            <div class="xiala">
                <div class="xiala1"> </div>
                <div class="xiala2"></div>

            </div>
        </li>
        <li>寿裳岬2号</li>
        <li>寿裳岬3号</li>

    </ul>
    2222
</body>
</html>